feat(io): add +open-with-default-app

Author: abougouffa

elisp/+io.el

@@ -337,6 +337,29 @@ current process."
     (delete-file (+lock--file name))
     t))
 
+(autoload #'mailcap-extension-to-mime "mailcap")
+
+;;;###autoload
+(defun +open-with-default-app (&optional file-or-url)
+  "Open FILE-OR-URL in the system's default application (via \"xdg-open\").
+
+When FILE-OR-URL is nil, try to guess a file/directory name or ask for one."
+  (interactive)
+  (let* ((file (or file-or-url
+                   ;; When in `dired', get file at point
+                   (and (derived-mode-p 'dired-mode) (dired-x-guess-file-name-at-point))
+                   (thing-at-point 'existing-filename)
+                   (thing-at-point 'url)
+                   (read-file-name "File or directory to open: " nil default-directory)))
+         (file-ext (file-name-extension file))
+         (file-mime (and file-ext (mailcap-extension-to-mime file-ext)))
+         (default-app (or (and file-mime (car (xdg-mime-apps file-mime))) "")))
+    (if (and file-mime (string-match-p "^emacs\\(client\\)?$" (file-name-base default-app)))
+        (progn (message "The default application for %S files (*.%s) is Emacs, openning with `find-file'." file-mime file-ext)
+               (find-file file))
+      (message "Opening %S with the default system application..." (abbreviate-file-name file))
+      (call-process-shell-command (format "xdg-open %S" (expand-file-name file))))))
+
 ;;;###autoload
 (defun +minemacs-root-dir-cleanup ()
   (let ((default-directory minemacs-root-dir))